Mandrel.



Vj -UNITED vSTATES PATENT OEEICE EDWARD i. .BRADDCCIQ oF WINCHESTER, MASSACHUSETTS, ASSIGNOR To HENRY W.. LAMB, E 'BRCCKLINE MASSACHUSETTS, AND DAVID A.` 'RITCHIE-OFCAMBRIDGE, MASSACHUSETTS. i l

' MANDREL.

SPECIFICATION forming pea ef Lettere patent No. viaoea, dated Jennery 13, i903. h

l Application filed December 23, 1901. Serial No. 86,873. (No model.)

To all whom it may concern?, I

Be it'known that I, EDWARD I. BRADDOCIQ -a citizenof the United States, residing in Winchester, inthe couutyof Middlesex and State of Massachusetts, have invented an Improvement in Mandrels, of which the following'descriptionglin connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

xo This invention relates to-a novel mandrel especially designed and adapted for use ini the manufacture of composite non-corrodible pipe, substantially such as shown and de` scribed in United States Patent No. 610,224,

x5 dated September 6, 1898. Y 1

In 'the practical manufacture of nonfcrrodible-pipe such 'as above referred to it has been ascertained that a mandrel composed wholly of metal, such as ironor steel, .is un zo suitable, or at least unreliable, for 'perfect work carried on continuously, or, as it Vmay be termed, in a practical manner,owing.to

the fact thatthe metal fmandrel' becomes coated by the molten metal, and when the z5 portion of the molten non-corrodible metal.

within the iron or steel tube and betweenit andthe mandrel issubjected to a chillingv action the noncorrodible metal contracts and adheres to the metal mandrel, thereby ren- 3o dering itdicult to move the mandrel with relation to the iron or` steel tube, or vice versa, and the non-corrodible metal adheres so firmly as to tear it away from the portion adhering to the iron or steel tube, thereby reducing the thickness of the non-corrodible tube in the composite pipe and also leaving a rougheedsur'face onthe interior of the' composite pipek 1 The object ofthis invention is to overcome Y 4o the objectionable features above referred to,

and -I accomplish thevdesired object by theA employment of a mandrel provided for substantially the greater -portion ot' its length with a nonmetallic surfaceof a material which is unaffected by the heat of the molten metal and towhich themolten metal does not adhere.

The non fmetallic material preferred by me and with which I have obtained excellent re- 5o sults ismica, and the desired length of nonmetallic surface I have obtained by assembling mica disks on a metal rod or support and compacting said disksfso as to practicallyform a cylinder or tube'of mica, as will Y be described. These and other features of this invention will be pointed out in the claims at the end of thisspecification.`

Figure 1 is an elevation of a mandrel embodying `this inventionand.Fig 2 a longitu-` dinalsection on the line 2 2 of the mandrel shown in Fig. 1 y

Referring to the drawings, a, represents a rod or supporting-core for a plurality of disks b, which --are mounted on` the core or vrod a. and are firmly compacted together by means of a head c onA one end ofthe rod a. and a nut d on the other end thereof.v The disks b are composed of a non-metallic substance which is unaected by molten tin, lead, zinc, or the like employed in the manufacture of the non- 7cv cured firmly` in place by the nut d may be turned downto the size or-diameter desired, so as to form practically a mica cylinder mounted on a metallic coreV or support and suitably confined in-place thereon. The mica cylinder mounted on the vrod a and the head c and nutd form acorn'posite mandrel, which 8o in practice may and preferably will be ati tached toa suitable r'od e, which, maybe of anyv desired .length and constitutes@ handle for or extensionof the mandrel. This attachment may be e'lected by acentering device, 85 which latter may be of any suitable construction, but preferably that herein shown, i con-4 sisting of a plurality of pieces f 4g h o like construction and assembled toformpractically a cylinder'provided at its opposite ends with internal grooves 1l j, one ofsaid grooves, as c', loosely engaging the headlc of a bolt or threaded rod Z, attached to the head c of the mandrel, a'nd the other ofsaid grooves, as j, engaging the headm of Vtherod e, to whicha collar n is attached,as by'a pin 0. (Shown by dotted lines, Fig. 2.)

The' head c of the mandrel is provided with a recess or socket p, into which project iingers q-on the front ends of the pieces consti- :cey

tuting the centeringdevice.' The pieces constituting the centering device are providedV at their rear ends with fingers 7', which extend into pockets s, formed in the collar n, as by partition-walls t.

The groove i is provided with avbeveled front wall u, which coperates'with the head vla of Ithe bolt or rodl to expand the centering device beyon`d the diameter of the mandrel and sufficient to engage the inner wall of the iron or steel pipe when strain is exerted upon' 'the rod e, thereby accurately centering the vention in this respect.

mandrel ,Within the said pipe and insuring the formation of a non-corrodible tube within the same of substantially uniform thickness.

Instead of the particular form of centering device herein shown other forms may be used.

c orrodible pipe, comprising a center rod provided at one end with an `enlargement or head, a plurality of disks of a material to which molten metal does not adhere and which is substantially unaffected by the heat of said molten metal, 4said disks being arranged on the said rod for substantially its length, and a metallic head fitted 4upon `the, free end of said rod to press the. disks in close contact with' one another to form a compact body, and to retain said disks in said compact form, substantially as described.

2.' A mandrel for forming composite noncorrodible pipe comprisingl a metallic center piece or rod,a plurality of mica disks mounted upon said rod in contactl with one another and Vfor substantially the length of said' center piece, and metallic end'pieces between which said mica disks are confined to form a compact body, substantially as described.

3. Amandrel composed of metallic portions Y and a plurality of interposed mica disks, substantially as described.

Inl testimony whereof I have signedmy name to this specification in the presence of two subscribing Witnesses.

` EDWARD I. BRADDocK.

Witnesses:

JAS. CHURCHILL, J. MURPHY. 

